The alleged drive-by shooter who late Friday night took six lives and his own during a chaotic killing spree in downtown Isla Vista, Calif., near the University of California campus, may have planned the event in careful detail, posting his intentions on YouTube just a day before he took to the streets in a black BMW armed with a semi-automatic hand gun.

Police say answers are quickly emerging to what they called the “highly complex crime scene” that unfolded in and around the populous Isla Vista area. For one, police say they are investigating a YouTube video made by a 22-year-old college student and posted Thursday. In the video, he describes his plans to shoot up Isla Vista to “exact retribution on all who deserve it.”

Santa Barbara County Sheriff Bill Brown described the shooter as a “disturbed individual,” and said the incident was “obviously the work of a mad man.” In addition to those killed, seven people were injured, several critically.

The shooting began at around 9:30 p.m. Friday night, and moved to various parts of downtown. The subject exchanged gunfire with police twice before he crashed. Police said there were nine separate crime scenes after a spree that lasted about 10 minutes.

Even as body bags could be seen laid out in various spots around the area, witnesses also reported a strange sense of normalcy, as some locals continued with their evening activities, including one young person doing his homework near one shooting site.

“Some people are curious what the [heck] is going on, and others are cruising around with 18-packs,” said Tyler Hayden, a news editor at the Santa Barbara Independent.

The notion of a drive-by shooting – where a quick getaway is more important than firing accurately – began in the Wild West, took deeper root in Prohibition-era Chicago, and has today become the de facto assassination technique for California gangs. Half of the country’s annual drive-by shootings take place in California.

But police say the shooter in Friday night’s incident seemed to be targeting people randomly. They believe he acted alone.

Sheriff Brown confirmed that material left by the college student on YouTube “appears to be connected” to the shootings. The Santa Barbara Independent said the car at the scene of the drive-by massacre has the same license plate as the car owned by the man in the video.

In the YouTube video posted a day before the shootings, the man bemoans an existence full of “loneliness, rejection and unfulfilled desires,” and chides women for being attracted to “obnoxious brutes” while rejecting “gentlemen” like himself.

Police have not yet confirmed the shooter’s name, and have not yet released the names of victims.

In his early morning press conference, Sheriff Brown said his department will soon share details giving a clearer picture of the gunman and his motivations. While acknowledging crime problems in and around Isla Vista, the sheriff said the shooting “could have occurred anywhere.”

Founded by dirt farmers in the 1920s, Isla Vista is today an unincorporated beachside community near Santa Barbara. Most of its 23,000 residents are college students, and the area is best known for its youthful beachside vibe and as a hotbed of garage bands.

The area was the site of a 2001 massacre by University of California student David Attias, who slammed his car into pedestrians and parked cars, killing four people. A court later found Mr. Attias to be legally insane.